The reaction between chloranilic acid and water in alcohol was studied spectrophotometrically. The conditions of reaction were investigated in detail. The stable purple complex with an absorption wavelength at 530 nm ...The reaction between chloranilic acid and water in alcohol was studied spectrophotometrically. The conditions of reaction were investigated in detail. The stable purple complex with an absorption wavelength at 530 nm was produced from the reaction between chloranilic acid and water. As a method for determination of H2O, Beer’s law was obeyed in range of 0-6.0 % or 0-8.0 % (V/V) with the detection limit of 0.13 %. The relative standard deviation (RSD) was less than 2 %. The proposed method has been applied to determination of trace amount of water in ethanol, flour and food flavoring, respectively. The recoveries of water in samples were 97～102 %.展开更多
The syntheses, spec(?) complexes are of significance for understanding mechanisms of magnetic interaction between metal ions and the exploitation of the synthesis of molecular magnetic materials. There were a few work...The syntheses, spec(?) complexes are of significance for understanding mechanisms of magnetic interaction between metal ions and the exploitation of the synthesis of molecular magnetic materials. There were a few works reported previously on the syntheses and magnetic in-展开更多
A spectrophotometric method for the assay of lamivudine in pure form and in dosage form was developed in this study. The method was based on charge-transfer complex formation between the drug, which acted as n-donor w...A spectrophotometric method for the assay of lamivudine in pure form and in dosage form was developed in this study. The method was based on charge-transfer complex formation between the drug, which acted as n-donor while chloranilic acid and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) acted as a p-acceptor in a non-aqueous solvent in each case. Chloranilic acid was found to form a charge-transfer complex in a 1:1 stoichiometry with lamuvudine (lamivudine-chloranilic acid) with a maximium absorption band at 521 nm. Also, DDQ was found to form a charge-transfer complex in a 1:1 stoichiometry with lamivudine (lamivudine-DDQ) with a maximium absorption band at 530 nm. The pH was obeyed at acid range. The complexes obeyed Beer’s law at a concentration range of 0.04 - 0.28 mg/ml. The thermodynamic parameters calculated at different temperatures included the molar absorptivity, association constant, free energy change, enthalpy and entropy. The proposed method has been conveniently applied in the analysis of commercially available lamivudine tablet with good accuracy and precision.展开更多
The interaction between amino acid drugs, aminobutyric acid, carbocisteine and levodopa, with chloranil was studied spectrophotometrically. The conditions were investigated and optimized. The interaction obeyed Beer＇...The interaction between amino acid drugs, aminobutyric acid, carbocisteine and levodopa, with chloranil was studied spectrophotometrically. The conditions were investigated and optimized. The interaction obeyed Beer＇s law over the range of 0.2-8.7, 1.2-20 and 2-26.4 μg/mL for aminobutyric acid, carbocisteine and levodopa, respectively. The validity was compared with that by the official methods^1,3,5 and the recovery studies of standard addition method, the result is satisfactory. The proposed method has been successfully applied to the determination of the above drugs in tablets.展开更多
文摘The reaction between chloranilic acid and water in alcohol was studied spectrophotometrically. The conditions of reaction were investigated in detail. The stable purple complex with an absorption wavelength at 530 nm was produced from the reaction between chloranilic acid and water. As a method for determination of H2O, Beer’s law was obeyed in range of 0-6.0 % or 0-8.0 % (V/V) with the detection limit of 0.13 %. The relative standard deviation (RSD) was less than 2 %. The proposed method has been applied to determination of trace amount of water in ethanol, flour and food flavoring, respectively. The recoveries of water in samples were 97～102 %.
基金Supported by the National Natural Science Foundation of China
文摘The syntheses, spec(?) complexes are of significance for understanding mechanisms of magnetic interaction between metal ions and the exploitation of the synthesis of molecular magnetic materials. There were a few works reported previously on the syntheses and magnetic in-
文摘A spectrophotometric method for the assay of lamivudine in pure form and in dosage form was developed in this study. The method was based on charge-transfer complex formation between the drug, which acted as n-donor while chloranilic acid and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) acted as a p-acceptor in a non-aqueous solvent in each case. Chloranilic acid was found to form a charge-transfer complex in a 1:1 stoichiometry with lamuvudine (lamivudine-chloranilic acid) with a maximium absorption band at 521 nm. Also, DDQ was found to form a charge-transfer complex in a 1:1 stoichiometry with lamivudine (lamivudine-DDQ) with a maximium absorption band at 530 nm. The pH was obeyed at acid range. The complexes obeyed Beer’s law at a concentration range of 0.04 - 0.28 mg/ml. The thermodynamic parameters calculated at different temperatures included the molar absorptivity, association constant, free energy change, enthalpy and entropy. The proposed method has been conveniently applied in the analysis of commercially available lamivudine tablet with good accuracy and precision.
文摘The interaction between amino acid drugs, aminobutyric acid, carbocisteine and levodopa, with chloranil was studied spectrophotometrically. The conditions were investigated and optimized. The interaction obeyed Beer＇s law over the range of 0.2-8.7, 1.2-20 and 2-26.4 μg/mL for aminobutyric acid, carbocisteine and levodopa, respectively. The validity was compared with that by the official methods^1,3,5 and the recovery studies of standard addition method, the result is satisfactory. The proposed method has been successfully applied to the determination of the above drugs in tablets.
